International Rugby Board chief medical officer Martin Raftery has conceded there may be a link between contact sports and Chronic Traumatic Encephalopathy, a form of dementia.

The RFU's head of medicine Dr Simon Kemp has previously said there is no proven association between head trauma and dementia, but Dr Michael Grey, a reader in motor neuroscience at the University of Birmingham's School of Sport, Exercise and Rehabilitation Sciences, disagreed. He said "we have very good evidence of the link between concussion and dementia."

And the IRB's Raftery has acknowledged a possible link. He said: "CTE is a form of dementia, and there are studies about boxers and American football players who have suffered repetitive head injuries, so we recognise that there might be a potential link.

"However, prevention is key and we have implemented an approach that is in line with expert recommendations to mitigate risk of long-term implications.

"They are to eliminate deliberate hits to the head, which is banned in rugby, implement strict graduated return to play protocols, which we have, and educate best practice technique."

Raftery is confident the IRB's concussion prevention, education, awareness and management guidelines are making an impact throughout the sport.

"The message is getting out there," he added. "Our Unions understand the importance, and players are now much better educated and understand why it would be foolish to ignore protocols.

"We continue to do as much as we can with respect to concussion research, and the IRB is taking the issue very seriously."